Numbness in the Hands – Neurological, Metabolic, and Vascular Causes

Numbness in the hands is a symptom resulting from a disturbance in nerve conduction or blood supply to the upper limbs. It is most commonly associated with carpal tunnel syndrome, cervical disc disease, or diabetic neuropathy, but it can also be a sign of a stroke requiring urgent intervention.

• The most common cause is carpal tunnel syndrome.
• Cervical disc disease can cause radiation to the limb.
• Diabetes promotes the development of peripheral neuropathy.
• A deficiency of vitamin B12 leads to nerve damage.
• Sudden unilateral numbness requires the exclusion of a stroke.

See also: Back pain – the most common causes, symptoms, and effective treatment.

Is carpal tunnel syndrome the most common cause of hand numbness?

Numbness in the hands often results from carpal tunnel syndrome.

In this condition, the median nerve is compressed in the carpal tunnel, causing paresthesia, tingling, and weakness of grip. Symptoms worsen at night and during repetitive hand movements.

Diagnosis is confirmed by an EMG test, which assesses nerve conduction.

Can cervical disc disease cause radiation to the arms?

Numbness in the hands can be a symptom of cervical disc disease.

Damage to the intervertebral discs in the cervical region leads to pressure on the nerve roots. Symptoms often radiate along the upper limb and may coexist with neck pain.

In advanced cases, an MRI is performed to assess the degree of pressure on the nerve structures.

Do diabetes and vitamin B12 deficiency cause neuropathy?

Numbness in the hands can be a consequence of peripheral neuropathy.

Diabetes is one of the most common causes of peripheral nerve damage. Chronic hyperglycemia leads to microcirculation disorders and degeneration of nerve fibers.

A deficiency of vitamin B12 causes demyelination of the nerves and can lead to permanent sensory disturbances if not diagnosed early.

When can numbness indicate a serious neurological condition?

Sudden onset of hand numbness, especially unilateral, can be a sign of a stroke.

In such cases, symptoms are often accompanied by speech disturbances, drooping of the corner of the mouth, or weakness of muscle strength. This requires immediate diagnosis and treatment.

Other causes include:

• Raynaud’s syndrome.
• Rheumatoid arthritis (RA).
• Hypothyroidism.
• Electrolyte disturbances, such as magnesium, potassium, or calcium deficiency.

Q&A

Is hand numbness at night dangerous?
It often results from carpal tunnel syndrome, but requires consultation if symptoms persist.

Is EMG painful?
The test may be uncomfortable, but it is short-lived and safe.

Are vitamin deficiencies a common cause?
Yes, especially a deficiency of vitamin B12.

When should you urgently see a doctor?
In the case of sudden, unilateral numbness accompanied by neurological symptoms.

Sources:

1. American Academy of Neurology Guidelines. Peripheral neuropathy.
2. Phalen GS. The carpal tunnel syndrome. Journal of Bone and Joint Surgery.
3. Tesfaye S et al. Diabetic neuropathy. Lancet.
4. O’Leary F et al. Vitamin B12 deficiency. BMJ.
5. NICE Guidelines. Stroke and transient ischaemic attack management.